Since ancient times, people have used lights in the sky to find their way. An experienced celestial navigator can find his or her way at night or in the daytime with great accuracy just by noting the positions of the points of light in the heavens above us. Such “celestial navigation” makes use of observed positions of the North star and other stars, the Sun, the Moon and certain planets to ascertain position and direction. Even a young child knows that the Sun rises in the East and sets in the West. By using a sextant or other measuring device, navigators ancient and modern have been able to nearly exactly ascertain their position (e.g., longitude and latitude) on the earth's surface.
Artificial lights can also be used to ascertain heading. For example, a sailor piloting a ship off the coast can estimate the direction and distance to port by observing the lights of cities, towns and lighthouses. Aircraft can ascertain position by observing many light beacons on radio towers or other structures.
In the electronic world, it is possible for a computer-based camera device or other light sensor or detector to automatically ascertain distance relative to man-made light sources by measuring the spacing between detected points of light or other illumination. If the detector “sees” two spaced-apart light sources as being close together, then the detector is relatively far away from the light sources. If the detector detects that the two spaced-apart light sources have “moved” farther apart, then the detector has moved closer to the light sources. Furthermore, just as someone familiar with the summer night sky can tell which direction they are looking simply by observing the orientation of patterns of the star constellations they see, a light detector provided with the appropriate processing capabilities (e.g., software and/or hardware) can determine some aspects of its orientation relative to point light sources based on received light pattern orientation.
Such principles can be used for various applications, including, but not limited to detecting some aspects of the orientation of a handheld or other pointing or control device relative to a variety of target surfaces, such as display surfaces. For example, using such techniques, it is possible to detect how a handheld pointing device is aimed toward a display or other presentation surface. Such a handheld pointing device may be for example as described in U.S. 2007/0066394 filed Sep. 15, 2006, incorporated herein by reference.
While many display devices, including, but not limited to, computer, television, graphical and other displays, are capable of generating and emitting light, such light emissions are generally for the purpose of conveying information to human eyes. For example, the electron beam scanning performed by a conventional television display or computer monitor causes display pixels to emit visible light in the form of visible images. Some in the past have used these same displays to generate machine-recognizable light targets (e.g., so-called “flying spot scanners”). In addition, some display light detection techniques have been commercially successful. For example, a so-called “light gun” was used with early Nintendo video games such as “Duck Hunt” to determine where on a display screen the user was aiming a simulated weapon. However, further improvements and additional techniques as possible and desirable.
The technology herein provides exemplary illustrative non-limiting systems, methods, devices and techniques for supplying convenient and effective targeting or “marking” light sources for use with presentation surfaces including but not limited to 2D and 3D video display systems. Useful non-limiting applications include electronic and non-electronic displays of all types such as televisions, computer monitors, light projection systems, whiteboards, blackboards, easels and any other presentation or other surface imaginable. Such targeting or marking can be used for example to control cursors, other symbols, or objects on electronic displays.
An exemplary illustrative non-limiting implementation provides an elongated member such as a bar shaped housing including spaced-apart point light sources. The point sources could be disposed within a housing of any shape, could be in separate housings, could be included in the display's housing, etc. In one exemplary illustrative non-limiting implementation, the elongated member may have first and second ends. A point source may be disposed on each end or anywhere else along the housing. In one exemplary illustrative non-limiting implementation, the spacing between the two spaced-apart point sources may be 20 centimeters or more. The point sources could be closer together or further apart.
In an exemplary illustrative non-limiting implementation, each point source comprises an array of plural point illumination sources. The plural point illumination sources in each array may be directional. The point sources may be aimed in different directions to provide different illumination patterns. For example, some (e.g., three) of the point sources can have a primary radiation directionality (lobes) that is substantially perpendicular to a front face of the bar-like structure, whereas other point sources can have primary radiation directionalities (lobes) that define acute angles with respect to such perpendicular direction. In one exemplary illustrative non-limiting implementation, some of the point sources are directed forward, while others are directed outwardly, and still others are directed inwardly with respect to the elongated member. Such expanded irradiation coverage area can provide advantages for multi-player games or the like where two or more spaced-apart detection devices each independently detect the point sources from different positions.
In one exemplary illustrative non-limiting implementation, the point sources can be generally oriented to emit light within a common horizontal plane or into different planes (e.g., some upwardly, some downwardly, etc.). Such 3D directionality can provide a potentially wider coverage area horizontally and/or vertically. The point sources could use a single point source in each array. The point source arrays could be oriented in varying directions or in the same direction.
In an exemplary non-limiting implementation of arrays with a plurality of point sources, the point sources in each array may emit the same or different light colors or frequencies of light. For example, one exemplary illustrative non-limiting implementation may provide, on each end of a rigid “marker bar” or other structure, an array of differently-aimed infrared point light sources, with the different point light sources emitting the same frequencies or wavelengths of infrared or other light. Other arrangements are possible.
In an exemplary illustrative non-limiting implementation, the elongated member may comprise a rigid bar or other structure that is especially adapted for mounting to the top, bottom, side or other dimension of an electronic display device such as a television set. Such light emitting bar structure can be mounted by a variety of convenient means including but not limited to adhesive tape, Velcro, gravity, interlocking parts, or any other desired mechanism. The device could also be affixed to a stand on which the display sits or to which the display is attached. Still other arrangements could provide structures that are integral or partially integral to display devices.
Additional aspects of exemplary illustrative non-limiting implementations include:                At least two discrete infrared ray emitting portions united by a rigid or semi-rigid connecting rod or other structure to provide easy handling and known spacing.        Point sources comprising plural light emitting diodes (LEDs) or other emitters having different primary irradiation directions—thereby expanding the infrared irradiation coverage area and potentially improving detection accuracy.        Exemplary spacing between infrared ray emitting portions greater than 20 centimeters or other desired spacing in one exemplary illustrative non-limiting implementation.        In one exemplary illustrative non-limiting implementation, a straight line connects the bright points of a number of LEDs in the infrared ray emitting portion in parallel with a long side of the bar or other structure to provide symmetry (i.e. the distances between the bright point of each LED and the long side of the bar are the same).        Infrared ray emitting portions located on opposite ends of a bar or other elongated structure, or spaced apart equally along the length of a bar or other structure.        Other exemplary illustrative non-limiting configurations provide plural infrared or other ray emitting portions connected by flexible filaments such as cords or any other connecting mechanisms.        Fixed or adjustable spacing between plural light sources. For example, a bar of adjustable length makes it possible to change the distance between two infrared ray emitting portions after manufacture (e.g., by users at time of installation).        You can place the Marker bar either above or below the TV screen.        Using a marker bar stand: Communication may be improved in some situations by mounting the Marker bar on the Marker bar stand. (For example: if the TV is sitting on the floor.) To do this, remove the protective film from the foam pads on the bottom of the Marker bar stand. For additional stability, you can add adhesive-backed foam tape from a supplied sheet. These can be supplied to both the top and bottom of the stand. If you are using the extra foam tape, remove the protective film from the piece on the top of the Marker bar stand. One can mount the Marker bar stand to the front edge of the surface the TV is sitting on, or to the top of the TV.        To ensure the best game play experience, it may be desirable to ensure that the front of the Marker bar is aligned close to the front of the TV with the center of the Marker bar aligned with the center of the TV. Reception may be improved by mounting the Marker bar to the top of the TV with a Marker bar Stand.        